Address your letter to the specific college department, graduate program or individual who signed your college acceptance letter. Identify yourself in the first paragraph of your letter. State that you are writing in response to the offer of admission to the school or program.
Express your gratitude to the college admissions department or the graduate department that accepted you. If you know their names, extend thanks to the individuals who made the decision to accept your application for enrollment.
State that you are accepting admission to the specific college or graduate program you plan to attend. Offer brief thanks to the people who wrote letters of recommendation and supported your application for enrollment.
Conclude your letter of acceptance for school by repeating your thanks. State that you are looking forward to attending the college or graduate program. Close with "Sincerely," and sign the letter above your typed name.